Device for stabilizing airplanes by means of wind-vanes



y 1934- L. CONSTANTIN ,956,755

DEVICE FOR STABILIZING AIRPLANES BY MEANS OF WIND VANES Filed March 27, 1931 Patented. May 1, 1934 DEVICE FOR STABILI ZING AIRPLANES BY MEANS OF WIND-VANES Louis Constantin, Paris, France Application March 27,

1931, Serial No. 525,810

In France April 5, 1930 5 Claims.

My invention relates to stabilizing devices for airplanes including wind-vanes,'and more particularly Constantin wind-vanes, and its object is to improve said stabilizing devices so that their working may be more efficient and reliable.

The improvement according to my invention essentially consists in a regulating device adapted to be operated by the pilot, which device is interposed between the wind-vane and the elevator, aileron or other control surface that is actuated by said wind-vane, said regulating device making it possible to modify at any time the correspondence that exists between the position of the wind-vane and that of said control surface actuated by said wind-vane.

A particular embodiment of my invention, in which the wind-vane serves to control through a cable and swing bar transmission the elevator of an airplane, will be hereinafter described with reference to the appended drawing given merely by way or example, and in which;

Fig. 1 is a diagrammatic view of that embodiment shown in vertical section;

Fig. 2 is an end view of a detail of the device according to my invention;

Fig. 3 shows the regulating device or mechanism.

In the drawing, the main supporting surface of the airplane is diagrammatically shown in W, the elevator in G, and the wind-vane for stabilizing the airplane about its transversal axis in P, the plane of symmetry of said wind-vane being shown in :c:c'. Wing W supports windvane P through a support S in which is' journalled the axis A of the wind-vane. On the other hand, the wind-vane can be rotated by means of hand lever L and rod b which act upon the longer basis 151 of the articulated trapezium that forms a part of the wind-vane.

The wind-vane acts on elevator G in the following manner:

Rod 15 of the wind-vane is rigidly connected to a pinion 1m adapted to rotate about axis A.

Said pinion p1 meshes with a pinion 102', on the axis of which is keyed pinion m which in turn meshes with pinion 104 which carries an arm d. Said arm d is articulated with a rod e and theretore, through two swing oars g and g1 and cables c and or, it operates elevator G.

It will be readily understood that:

, 1. If the relative wind that was directed along :vm"is deviated forsome reason, and is, for instance, slightly upwardly directed, the surfaces of the wind-vane will also be moved in an upward direction, and the rear part of the elevator will be lowered, which is the correct move to be eifected in order to bring the airplane back to its original angle of attack;

2. It the wind-vane is rotated in a downward direction, by means of lever L and rod b, through an angle 0:, arm (1 will be rotated toward the rear through an angle a the mean value of which will most often be difierent from on because of the reaction of the control, and the rear part of elevator G will be moved upwardly by rotating through an angle ,8.

Now, the following consideration is to be taken into account for obtaining a good working of my device:

To each value of B- and therefore of a will correspond, for a given glider, an angle of attack Whatever the dimensions of d and g1 may be, it is only exceptionally that angles [3 and 0: will correspond to the angle of wing W and only one.

of rotation on in such manner that or may be equal to or that is to say that the mean position of the wind-vane may be merely rotated in a downward direction through an angle equal to a.

Now,

it is necessary that said condition be fulfilled to obtain a satisfactory working of the whole in rough weather.

On the other hand, a glider is characterized,

from the point of view of flight, not only by the disposition of its surfaces, but also by the position of its centre of gravity. Now the position of said centre of gravity depends essentially on the position of the load. And this latter position is itself essentially-variable from one flight to the other, and even during one flight, due togradual unloading. It results therefrom that to each position of the centre of gravity must correspond for the same angle of incidence, a different value of ,8.

H, is diagrammatically shown in Fig. 3.

Cables 0 and 01, instead from passing directly from g to g1 are so'arranged as to pass over six Pulleys qs, qr, as and On the pulleys qr, qz, Q2, 14, 15, 1

qe are mounted about stationary axes.

contrary, the axes of pulleys g1 and q; are mounted at the ends of a rack C which. may be moved upwardly or downwardly through rotation of a toothed wheel R, driven by means of a hand wheel V .(shown in dotted lines) which may be,

operated by the pilot.

It will be readily understood that any upward motion of rack C and pulleys qi, qz will result in shortening the active part of cable 0 and lengthcning the active portion of cable 01 and will thereffore involve a modification of the respective position' of arm d and swing arm g1. Inversely, a downward displacement of rack C will produce a lengthening of cable 0 and a shortening of cable or in the same manner as above explained.

I have thus provided a correcting device which makes it possible to adjust during the flight the position of the elevator so as to ensure flight at the desired angle of attack, which angle of attack depends both upon the position of L and upon the reaction of the control, while keeping, in calm weather, the wind-vane in its mid-position, that is to say ready to effect the most chi-- cient correcting displacements in rough Weather.

Said device may, of course, be replaced by any other equivalent mechanical device capable of permitting modification at will during the flight, of the respective positions of arm (1 and swing bar 91. For example, the same result might be obtained by modifying during the flight the.

length of rod e.

Although I have described what I deem to be a practical and eflicient embodiment of my invention it should be well understood that I do not wish to be limited thereto as my invention is subject to many and all structural variations which come within the scope of the appended claims.

What I claim is:

l. A stabilizing device for airplanes comprising a wind-vane of the general type described, including two parallel rods and two non-parallel rods articulated to each other so as to form an articulated trapezium, one of the last mentioned rods being pivotally mounted on the airplane, a

pinion rigidly connected to said last mentioned rod and adapted to rotate coaxially therewith, an arm pivotally mounted on the airplane, a plurality of gear wheels for actuating saidarm from said pinion, a control surface pivotally mounted on the airplane, a bar rigidly connected to said surface and extending on either side thereof, a bar pivotally mounted about an intermediate point of its length on.the airplane, a rod for connecting said arm to said last mentioned bar, two cables connecting the corresponding ends of said bars to each other respectively, and regulating means adapted to be operated by the pilot for shortening one of said cables and lengthening the other one.

- 2. A stabilizing device according to claim 1 in which the regulating means for simultaneously shortening one of the cables and lengthening the other one comprise two ilxed pulleys for maintaining one of said cables, two fixed pulleys for maintaining the other one, a rack disposed transversely with respect to said cables, a pulley at one end of said rack for supporting the first cable, a pulley at the other end of said rackfor supporting the other cable, a pinion for imparting a sliding motion to said rack, and a hand wheel adapted to be operated by the pilot for actuating said pinion.

3. In an airplane, a stabilizing device comprising in combination, a wind-vane of the general type described including two parallel rods and two non-parallel rods articulated to each other so as to form an articulated trapezium, one of the last mentioned rods being pivotally mounted on the airplane, means for adjusting the position of one of the two parallel rods with respect to the airplane, an arm pivotally mounted on the airplane, means for operatively connecting said arm with one of the two non parallel rods, a control surface pivotally mounted on the airplane, a bar rigidly connected to said surface and extending on either side thereof, a bar pivotally mounted aboutan intermediate point or its length on the airplane, a rod for connecting said arm with the last mentioned bar, two cables connecting the corresponding ends of said bars to each other respectively, and regulating means adapted to be operated by the pilot for shortening one of said cables and lengthening the other one.

4. In an airplane, a stabilizing device comprising in combination, a wind-vane of the general type described including two parallel rods ano two non-parallel rods articulated to each other soas to form an articulated trapezium, one of the last mentioned rods being pivotally mounted on the airplane, means for adjusting the position of one of the two parallel rods with respect to the airplane, an arm pivotally mounted on the airplane, means for operatively connecting said arm with one of the two non-parallel rods, a control surface pivotally mounted on the airplane, a bar rigidly connected to said surface, a bar pivotally mounted about an intermediate point of its length on the airplane, means forconnecting said arm with the last mentioned bar,ltwo cables connecting the corresponding ends of said bars to each other respectively, and regulating means adapted to be operated by the pilot for shortening one of said cables and lengthening the other one.

5. In an airplane, a stabilizing device comprising in ,combination, a wind-vane of the general type described including two parallel rods and two non-parallel ro ds articulated to each other so as to form an articulated trapezium, one of the last mentioned rods being pivotally mounted on the airplane, means for adjusting the position of one of the two. parallel rods with respect to the airplane, an arm pivotally mounted on the airplane, means for operatively connecting said arm with one of the two non-parallel rods, a control surface pivotally mounted on the airplane, means for operatively connecting said surface with said arm and regulating means adapted to be operated by the pilot for modifying the relative position of the control surface with respect no I 

